401-425 or 400-430-455?

Ok Guys,which was a better design engine as in cam bearings,oiling etc.... the 401-425 Nailheads? or the 400-430-455`s?but look at it not only in a power choice,look as for designed better?who can answer this?


Thanks

 

George,
I am surprised at the amount of people here in Kingman Arizona, that know what a 65 Buick GS is, and what the nailhead engine is. I have had several people stop and ask if my car is a GS, and this usually ends up with them telling me things about the one that they owned way back when. I was a car nut most of my life and use to drag race a long time ago in the era of the 426 Hemi's 427/396 chevelle's 427/406 Ford's 383/440 Roadrunner'and I am talking the classic muscle car days. Back then I never saw or heard of a Buick other than TV Tommy, that any one raced. That doesn't mean that no one was racing them, I just don't remember any. My point is this, I wish I had known back then what a Nailhead engine was and maybe I would have tried to find and race a Buick. I have learned a great deal about this wonderful engine design and have no opinion as to which is the best design the nailhead or later big block engines such as the 455's on down, The only thing I do know is this,I feel like I am in a time machine when ever I get behind the wheel if my GS. Take care George, ENJOY!
Bill Bailey

 

The nailhead was Buick's first v-8 and bowed in 1953 for the 50th anniversary. Because the cars were straight 8's up to that point, the engine was designed to be narrow to fit in the engine bays. It was a reliable and powerful engine and reportedly left the scene because a new engineer took over and wanted to put his own stamp on Buick engines. Its weakness was chiefly its heads which were canted steeply upward, which hampered airflow. They were also heavy. They were highly respected in circletrack racing due to their indestructible nature, and good engine braking, which allowed the drivers to spare the brakes when setting up for turns. They were supplanted by the cheaper and lighter smallblock chevys. It can be argued that a redesign of the heads would have extended the life of the nailhead, but the thinwall designs were light, strong, and well designed with knowledge gained in the previous 13 years. The Achilles heal of the thin walls is the bottom end and two bolt mains, which are prone to flex at high load, which limits the life of the engine if it is modified to make over around 600 or 700 horsepower. There are some neat vids and pics out there which show the bottom ends of 455 engines flexing harmonically and being blown apart downward by engines making over about 800 horsepower. There are main girdles available that really help the problem. Oiling is another issue, entirely, but the thin walls definitely have better topend oiling beginning with the tubular pushrods. The cast aluminum rocker arms were a pretty mistake that was corrected by stamped steel around 1971. Either way, both motors were worlds better than the corporate engines that GM decided to use in later models.

 

Hey Dan, are you referring to the 430 cast aluminum rocker arms? I know the '67 model run was weak, but I thought the fix they had for 68/69 was OK. Were they then dropped in 1970 due to cost? I can't imagine those silly plastic buttons holding the rockers are better than the full casting on the 430 style.

Just curious.

 

Got any links to these videos?

Bill S.

 

Yea,i`d be interested in seeing those also.


Thanks

 

I know this sounds funny, but I saw the engine test about two years ago as a link. I think it was one of the guys in the Northeast chapter of the GS club that did it to show why a stud girdle is important. I think Mike Tomascewski was involved somehow. You could see the engine mains flexing harmonically under high load and high revs. I didn't see it blow, but there were pics of a 455 with the main journals ripped out.
I rebuilt my Stage motor in 1987 or 88 and it had a bad rocker tick. When I removed the valve covers, it had the original cast aluminum rocker arms, and one had lost a decent sized piece of metal at the valve surface. I swapped out some stamped '71 pieces and went on my way. I kept the rockers, and they sure are pretty, but pretty don't get the wood chopped around here, ha, ha.